Poisoning Your Lover’s Coffee. Or Tea. Or Smoothie. Or…

Late last week, a doctor at Houston’s M.D. Anderson Cancer Center was charged with poisoning a “colleague.” Yes, he was a professional colleague, but reportedly he and the accused poisoner, Dr. Anna Maria Gonzales-Angulo, were also lovers, suggesting that things are lot more interesting behind the scenes at Anderson than many of us had realized.

As the story was explained, Gonzales-Angulo invited her, um, colleague, Dr. George Blumenchein over for a cup of coffee. He expressed some surprise when she served it sweet as he was a black coffee drinker. She assured him that it was just an artificial sweetener, pressed a second cup on him. He obligingly downed them both. A few hours later, he started feeling sick, within sixteen hours he was in an emergency room. He was lethargic, stumbling, blurring his words and – it would be discovered – sliding into renal failure. His treatment would eventually require dialysis.

If you are into toxicology (hand up here), there are two clear giveaways in the above description of events. One is the sweetness of the coffee. The second is the distinctive kidney damage. And, in fact, Dr. Gonzales-Angulo was charged with aggravated assault by use of the famously sweet, notably kidney-damaging poison, ethylene glycol. She’s denied those charges, and, as has been noted, there’s no known motive, so let’s expect a few more twists.

And that’s okay because it’s the poison itself – or rather the poison’s much longer and much more twisted history – that I want to explore here. Much of the coverage has tended to emphasize the fact that this is a compound easily available to the physician suspect because its a solvent used in medical research and routinely stocked at places like M.D. Anderson. But it’s much more available than that. Because it has a very low freezing temperature, this is better known as the primary compound in many commercial coolant and antifreeze formulas.

Chemically, it’s nothing particularly complex – a neatly organized bundle of carbon, hydrogen and oxygen (C2H6O2) – discovered by a French scientist in the mid-19th century. There was a gradual realization that this was a rather poisonous chemical bundle; in the 1920s, physicians considered using it as a solvent for medicines to be injected into patients. That, obviously, didn’t last, as you’ll see from this 1931 paper on its toxic properties (paywall). And you can track the growing respect for the compound in papers that followed; this one estimating that it caused 40-60 deaths a year in 1960, this one noting about 20 deaths a year (and thousands of accidental exposures) in the late 1990s.

So what makes it so dangerous? Like ethanol (the primary alcohol in drinkable spirits) it’s moderately neurotoxic – the slurring and stumbling symptoms shown by the poisoned doctor in Texas are classic signs of ethylene glycol intoxication. But the main danger comes less from such direct effect and more from the way we metabolize it. As enzymes break it down, a cascading chemical reaction creates a rising tide of oxalic acid in the bloodstream. The acid combines with calcium to form calcium oxalate crystals. These envelope-shaped, sharp-edged crystals do harm in a number of organs but they tend to concentrate in the kidneys – where they neatly slice cells apart. In other words, it’s not surprising that after swallowing two cups of ethylene glycol laced coffee, the M.D. Anderson doctor ended up requiring dialysis.

But the other point here is that he was – allegedly, at least – so easily persuaded to drink that laced coffee. So unsuspecting of the taste. And that brings me to the another point about ethylene glycol. In pure solution (as found at places like Anderson) it’s colorless and odorless. And – in this form, in a container of antifreeze, in any of its applications – from the poisoner’s point of view, it offers another advantage – it’s rather seductively sweet.

(In fact, it’s sweet enough to pose a risk to pets who may wander into a garage and lick up a puddle of antifreeze which may have dripped from a car radiator. “Antifreeze poisoning is one of the most common forms of poisoning in small animals,” according to PetMD. It’s also favored by people who poison their neighbor’s pets (a subject I’ve written about before) as seen in this recent case from Britain and this one from the United States. And it’s one of the most common poisons chosen by people who want to kill other people as well.)

And the pet poisoning angle should emphasize another point here. This is not some special toxic compound uniquely available to medical researchers – it’s a garden-variety substance, the kind of poison located in countless garages and businesses. That’s why it turned up in all those medical risk reports I cited earlier. And that’s why, unfortunately, it tends to be one of our favorite homicidal poisons.

Let me count the ways, or at least a few of them:

Well, there was Lynn Turner, from Atlanta, Georgia, who killed two husbands (the first in 1997 and the second in 2001) by feeding them Jello laced with antifreeze. This should give you a good idea of just how mild and sweet the taste is. She was caught on the second murder and died in prison in 2010, reportedly by taking an overdose of her blood pressure medication. There was Stacy Castor, of Clay, New York, convicted in 2007 of killing her husband with antifreeze and then trying to murder her stepdaughter by mixing it into a cocktail of vodka, orange juice and Sprite. There was Serena York, of Vernal, Utah, who poisoned an elderly neighbor by mixing antifreeze into a peach smoothie in an effort to get his money. The Cleveland woman charged with killing her fiance by slipping it into his raspberry tea. The New Jersey woman accused last year of poisoning her husband’s grandmother because she was tired of giving her a home. And the really horrifying case of a couple years ago in which an Alabama couple were charged with killing their three-year-old daughter and four-year-old son with antifreeze because they were “tired of the responsibility.”

In other words, there’s nothing especially doctor-special about this poisoning in Texas. If the charges hold up, then we’re looking at nothing more than one more person – angry, bitter, resentful – who decides to send a message with the help of a time-tested poison. It doesn’t tell us that physicians are somehow smarter about this. It tells us that the most dangerous people – and substances – in our lives are often the ones we encounter every single day.